/*
 * Copyright (C) 2005-2011 MaNGOS <http://www.getmangos.com/>
 *
 * Copyright (C) 2008-2011 Trinity <http://www.trinitycore.org/>
 *
 * Copyright (C) 2010-2011 ProjectSkyfire <http://www.projectskyfire.org/>
 * 
 * Copyright (C) 2011 ArkCORE <http://www.arkania.net/>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

/** \file
 \ingroup realmd
 */

#include "RealmSocket.h"

#include "Log.h"

#include <ace/OS_NS_string.h>
#include <ace/INET_Addr.h>
#include <ace/SString.h>

#ifndef MSG_NOSIGNAL
#define MSG_NOSIGNAL 0
#endif

RealmSocket::Session::Session(void) {
}

RealmSocket::Session::~Session(void) {
}

RealmSocket::RealmSocket(void) :
		input_buffer_(4096), session_(NULL), remote_address_() {
	reference_counting_policy().value(
			ACE_Event_Handler::Reference_Counting_Policy::ENABLED);

	msg_queue()->high_water_mark(8 * 1024 * 1024);
	msg_queue()->low_water_mark(8 * 1024 * 1024);
}

RealmSocket::~RealmSocket(void) {
	if (msg_queue())
		msg_queue()->close();

	// delete RealmSocketObject must never be called from our code.
	closing_ = true;

	if (session_)
		delete session_;

	peer().close();
}

int RealmSocket::open(void * arg) {
	ACE_INET_Addr addr;

	if (peer().get_remote_addr(addr) == -1) {
		sLog->outError("RealmSocket::open: peer ().get_remote_addr errno = %s",
				ACE_OS::strerror(errno));
		return -1;
	}

	remote_address_ = addr.get_host_addr();

	// Register with ACE Reactor
	if (Base::open(arg) == -1)
		return -1;

	if (session_ != NULL)
		session_->OnAccept();

	// reactor takes care of the socket from now on
	remove_reference();

	return 0;
}

int RealmSocket::close(int) {
	shutdown();

	closing_ = true;

	remove_reference();

	return 0;
}

const std::string& RealmSocket::get_remote_address(void) const {
	return remote_address_;
}

size_t RealmSocket::recv_len(void) const {
	return input_buffer_.length();
}

bool RealmSocket::recv_soft(char *buf, size_t len) {
	if (input_buffer_.length() < len)
		return false;

	ACE_OS::memcpy(buf, input_buffer_.rd_ptr(), len);

	return true;
}

bool RealmSocket::recv(char *buf, size_t len) {
	bool ret = recv_soft(buf, len);

	if (ret)
		recv_skip(len);

	return ret;
}

void RealmSocket::recv_skip(size_t len) {
	input_buffer_.rd_ptr(len);
}

ssize_t RealmSocket::noblk_send(ACE_Message_Block &message_block) {
	const size_t len = message_block.length();

	if (len == 0)
		return -1;

	// Try to send the message directly.
	ssize_t n = peer().send(message_block.rd_ptr(), len, MSG_NOSIGNAL);

	if (n < 0) {
		if (errno == EWOULDBLOCK)
			// Blocking signal
			return 0;
		else
			// Error happened
			return -1;
	} else if (n == 0) {
		// Can this happen ?
		return -1;
	}

	// return bytes transmitted
	return n;
}

bool RealmSocket::send(const char *buf, size_t len) {
	if (buf == NULL || len == 0)
		return true;

	ACE_Data_Block db(len, ACE_Message_Block::MB_DATA, (const char*) buf, 0, 0,
			ACE_Message_Block::DONT_DELETE, 0);

	ACE_Message_Block message_block(&db, ACE_Message_Block::DONT_DELETE, 0);

	message_block.wr_ptr(len);

	if (msg_queue()->is_empty()) {
		// Try to send it directly.
		ssize_t n = noblk_send(message_block);

		if (n < 0)
			return false;
		size_t un = size_t(n);
		if (un == len)
			return true;

		// fall down
		message_block.rd_ptr(un);
	}

	ACE_Message_Block *mb = message_block.clone();

	if (msg_queue()->enqueue_tail(mb, (ACE_Time_Value *) &ACE_Time_Value::zero)
			== -1) {
		mb->release();
		return false;
	}

	if (reactor()->schedule_wakeup(this, ACE_Event_Handler::WRITE_MASK) == -1)
		return false;

	return true;
}

int RealmSocket::handle_output(ACE_HANDLE /*= ACE_INVALID_HANDLE*/) {
	if (closing_)
		return -1;

	ACE_Message_Block *mb = 0;

	if (msg_queue()->is_empty()) {
		reactor()->cancel_wakeup(this, ACE_Event_Handler::WRITE_MASK);
		return 0;
	}

	if (msg_queue()->dequeue_head(mb, (ACE_Time_Value *) &ACE_Time_Value::zero)
			== -1)
		return -1;

	ssize_t n = noblk_send(*mb);

	if (n < 0) {
		mb->release();
		return -1;
	} else if (size_t(n) == mb->length()) {
		mb->release();
		return 1;
	} else {
		mb->rd_ptr(n);

		if (msg_queue()->enqueue_head(mb,
				(ACE_Time_Value *) &ACE_Time_Value::zero) == -1) {
			mb->release();
			return -1;
		}

		return 0;
	}

	ACE_NOTREACHED(return -1);
}

int RealmSocket::handle_close(ACE_HANDLE h, ACE_Reactor_Mask /*m*/) {
	// As opposed to WorldSocket::handle_close, we don't need locks here.

	closing_ = true;

	if (h == ACE_INVALID_HANDLE)
		peer().close_writer();

	if (session_ != NULL)
		session_->OnClose();

	reactor()->remove_handler(this,
			ACE_Event_Handler::DONT_CALL | ACE_Event_Handler::ALL_EVENTS_MASK);
	return 0;
}

int RealmSocket::handle_input(ACE_HANDLE /*= ACE_INVALID_HANDLE*/) {
	if (closing_)
		return -1;

	const ssize_t space = input_buffer_.space();

	ssize_t n = peer().recv(input_buffer_.wr_ptr(), space);

	if (n < 0)
		return errno == EWOULDBLOCK ? 0 : -1;
	else if (n == 0) // EOF
		return -1;

	input_buffer_.wr_ptr((size_t) n);

	if (session_ != NULL) {
		session_->OnRead();

		input_buffer_.crunch();
	}

	// return 1 in case there is more data to read from OS
	return n == space ? 1 : 0;
}

void RealmSocket::set_session(Session* session) {
	if (session_ != NULL)
		delete session_;

	session_ = session;
}
